public class Test1 {
    public static void main(String[] args) {
        //了解String和StringBuilder的区别
//        String s = "";
//        for (int i = 0; i < 1000000; i++) {
//            s = s + "abc";
//        }
//        System.out.println(s);

          StringBuilder s1 = new StringBuilder();
        for (int i = 0; i < 1000000; i++) {
            s1.append("abc");
        }
        System.out.println(s1);

    }
}
